In 2008, NASA reorganized in order to align itself with the new Vision for Space Exploration. The reorganization clarified organizational roles with the creation of four mission directorates: Aeronautics Research Mission Directorate, Human Exploration and Operations Mission Directorate, Science Mission Directorate, and the Space Technology Mission Directorate. These directorates manage the many missions NASA undertakes, and they address the need for an integrated approach to science requirements, management and implementation of the missions. Each mission directorate now covers a major area of NASA's research and development efforts. The NASA budget for each of the four directorates can be found under the NASA Budget tab.
Updated November 2020 by Kristen Johnson